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The present invention generally relates to methods and compositions for treating the natural cane reed used in woodwind instruments, employing a polymer or polymerizing solution, preferably a waterborne polymer or waterborne polymerizing solution, to impregnate and protect the reed from saliva-related microbial and enzymatic degradation, without rendering the reed waterproof.
The wooden reed used in woodwind instruments is usually cut from natural cane (e.g., the species Arundo donax). Being highly porous, the reed is susceptible over time, to infiltration and degradation by contact with saliva during playing. As a musician blows air over a cane reed, which is typically clamped at its distal end or xe2x80x9cheelxe2x80x9d in the instrument""s mouthpiece, the reed is caused to vibrate, thereby inducing vibrations in the moving column of air within the instrument to produce musical tones. During a single playing session, the physical and musical properties of a reed may change for the better or worse. This is not surprising, because even after several minutes pre-soaking, i.e., xe2x80x9cconditioning,xe2x80x9d of the mouth end of the reed in water, the subsequent contact with warm saliva during a playing session tends to further soften the reed. Some softening may be beneficial during the initial breaking-in period when a reed is new and somewhat unresponsive. However, after an initial period during which the reed may become optimally playable (over a few days or even after a week or more), any further softening may be undesirable. That is, as the cane structure becomes degraded and the reed becomes too flexible, the reed must be discarded.
There is considerable variability in the sound quality and longevity of individual cane reeds, even within a group of presumably equivalent reeds from any particular manufacturer. In fact, a musician may find that no more than one or two out of every ten reeds possess ideal tone and playing characteristics. Due to difficulties and frustrations with the lack of uniformity and short lifetime of natural cane reeds, a number of synthetic reeds, composite reeds and structurally reinforced natural reeds have been developed. A number of exemplary patents detailing such structurally modified reeds follows. Fiber-reinforced plastic reeds are described in Brilhart, U.S. Pat. No. 2,919,617. Reeds containing glass fiber-reinforced synthetic resin are described in Burns, U.S. Pat. No. 3,165,963. Synthetic reeds are described in Gamble, U.S. Pat. Nos. 3,905,268 and 4,014,241. Shaffer, U.S. Pat. No. 4,355,560, describes a synthetic composite reed structure producing an acoustic impedance similar to the cane reed. Backus, U.S. Pat. No. 4,337,683 describes a graphite-reinforced epoxy resin synthetic woodwind reed having proper elasticity and density. Cusack et al., U.S. Pat. No. 5,227,572 describes a titanium reed for woodwind instruments. Hartmann et al., U.S. Pat. No. 5,542,331 describes a fiber-reinforced plastic reed in which different fiber materials are combined for the purpose of damping vibrations.
Extending the lifetime of natural cane reeds has been the goal of a number of previous inventors. These inventors have appreciated that in addition to mechanical fatigue, degradative enzymes, bacteria and other constituents of human saliva infiltrate the porous structure of the cane reed during use, and contribute to a shortened lifetime. Reed failure may occur suddenly, as when the tip of the reed splits, or may occur gradually as the reed softens and loses tone quality. Rinsing the reed is only partially effective in removing enzymes, bacteria and saliva residues. Vogt, U.S. Pat. No. 5,379,673, describes a hydrogen peroxide and humectant-containing composition for soaking, disinfecting and conditioning natural cane reeds after use, to prolong their life.
To inhibit the process of reed degradation by saliva, inventors have developed a number of protective coating treatments for the natural cane reed. As early as 1930, Newton et al., U.S. Pat. No. 1,776,566, describes reeds for musical instruments whose pores have been adequately filled with cellulose or nitrocellulose in an organic solvent, to render the reed waterproof and resistant to the destructive action of the juices of the human mouth. Ogilvie, U.S. Pat. No. 1,790,167, describes a thin, flexible coating of celluloid material, applied in a quick-drying organic solvent to the surface of the cane reed in such a manner that the reed surface becomes waterproof while the pores inside of the reed remain open, i.e., empty. Petzke, U.S. Pat. No. 3,340,759, describes a natural cane reed whose pores have been impregnated with a cured vinyl plastisol. The plastisol is described as a synthetic resin which is essentially 100% solids, and free of solvents or diluents which would evaporate and cause undesirable shrinkage. The pores of the reed are substantially sealed to prevent moisture absorption, thereby rendering the reed waterproof. Similarly, Knotik et al., U.S. Pat. No. 3,705,820, describes wind instrument reeds which have been soaked in partially polymerized methylmethacrylate which is then polymerized in the reed by ionizing radiation. This treatment fills the pores, effectively waterproofing the reed, and controlling moisture-induced swelling and loss of elasticity.
Other sealing coatings which are applied externally to the natural cane reed have been described. Killian, U.S. Pat. No. 4,145,949, describes a natural cane reed having a thin protective coating of fine particulate matter, e.g., metallic powder, deposited on the tip and edges of the reed but not on the heart or main vibratory section of the reed. A plastic-coated cane reed is also described by Rico International (Sun Valley, Calif.) for musicians who have a limited amount of control over their playing environment or need instant playability without having to re-wet their reeds. These plastic coated reeds have improved durability compared to uncoated reeds, but have playing characteristics which differ markedly from the uncoated natural cane reed.
This invention features methods and compositions for treating the natural cane reed used to produce musical tones in woodwind instruments. The treatment utilizes a polymer or polymerizing solution, preferably a waterborne polymer or waterborne polymerizing solution, to impregnate the reed, but not render the reed waterproof. The absorbed polymer protects the reed from microbial and enzymatic degradation, thereby extending the lifetime of the reed. Surprisingly, this protection can be achieved while allowing the reed to absorb essentially normal levels of moisture from the mouth. The normal playing characteristics of the original reed are thereby either sustained or enhanced over the lifetime of the reed by the treatment.
Preferably a non-toxic waterborne polymer (or other suitable solvent-borne polymer), polymer suspension, polymer emulsion, or an aqueous-based (or other suitable solvent-based) polymerizing solution (collectively termed xe2x80x9cwaterborne or aqueous polymer treatment liquid,xe2x80x9d xe2x80x9cpolymer treatment liquid,xe2x80x9d or simply xe2x80x9cpolymer liquidxe2x80x9d) is used to impregnate the reed material. xe2x80x9cPolymer liquidxe2x80x9d and similar terms shall refer to both aqueous and non-aqueous liquids unless indicated to the contrary, e.g., a non-aqueous polymer liquid, an aqueous polymer liquid, or an alcoholic polymer liquid. This impregnation can be accomplished by submersion of the entire reed, or at least submersion of the proximal portion, i.e., the mouth-end portion, of the reed, in the polymer liquid under conditions that provide sufficient polymer uptake to provide degradation-resistance, e.g., a liquid contact period of at least 0.5 hr at room temperature and one atmosphere. Impregnation may be accelerated (and the treatment period reduced) by methods well known in the art, including reducing the external pressure over the reed prior to impregnating the reed, and then increasing the external pressure to accelerate the entry of polymer into the pores of the reed. While the use of waterborne polymer treatment liquids are preferred, other liquids can also be used, e.g., alcohols such as ethanol and isopropanol. Preferably, the liquid is non-toxic, at least at residual levels. While the aspects of the present invention are described in connection with exemplary aqueous solutions or emulsions, other embodiments involve other liquids as just indicated. Therefore, the descriptions herein apply to both aqueous and non-aqueous liquids, though aqueous liquids are preferred.
Following contact with the polymer liquid during impregnation, free liquid residing on the surface of the reed is wiped away or otherwise substantially removed. This removal step is useful because the excess polymer material would otherwise dry on the reed surface and might undesirably seal the surface and pores of the reed, rendering it waterproof. The fact that the reed remains water-permeable after the polymer inside the reed has been allowed to dry or cure, has been demonstrated by gravimetric measurement of the rates of water absorption over a 30-60 minute period, comparing the untreated reed with the polymer-treated reed. At a minimum, the initial rate of liquid absorption under specified conditions for the treated reeds (e.g., total weight of water absorbed during the first 30-60 minutes of water immersion, divided by the time of immersion, measured at 22xc2x0 C. and one atmosphere) remains equal to, or greater than 25% of the rate of liquid absorption for the untreated reed. Preferably, the rate of liquid (e.g., water) absorption for the treated reed remains equal to, or greater than 30%, 40%, 50%, 60% or even more, compared to the rate of absorption for the untreated reed. In many instances, though not necessaily, both the rate and the total amount of liquid (e.g., water) absorption after 10, 30 and 60 minutes of submersion in liquid (e.g., water) for the treated and untreated reeds are very similar (see Examples 1 and 2 below).
Thus, in the present invention, the polymer coating which protects the reed against degradation by saliva, microbial flora, and the like, is formed not as an outer waterproof barrier on the reed surface, but as a coating within the microscopic channels of the porous reed matrix, i.e., within the pores, channels and interstices of the reed. This xe2x80x9cinternallyxe2x80x9d protective polymer coating, that allows entry of water into the reed, differs markedly from both the space-filling pore-sealants and the waterproof exterior coatings formed on reeds described in other patents. Most importantly, the playing characteristics and musical sound quality of the untreated reed, are substantially preserved, i.e., sustained in the treated reed. Applicant believes that sustaining a substantial degree of water-permeability in the treated reed may be an important element in preserving many of the original sound characteristics of the untreated reed.
Typical preferred examples of useful aqueous polymer treatment liquids, include water-based emulsions (largely free of organic solvents) from the polyurethane polymer family, water-based emulsions from the polyacrylate polymer family, and combinations thereof. The proportion of polymer solids in the aqueous polymer treatment liquid is between 10% and 60% by weight, preferably 25%-40% by weight. In contrast to Petzke, U.S. Pat. No. 3,340,759, which utilized a resin containing 100% solids, the presence of a substantial proportion of water or other appropriate solvent in the present polymer treatment liquid is advantageous. This is because after the water component in the treatment liquid has evaporated, and normal curing and/or shrinkage of the polymer has occurred, the pores and channels within the reed will remain open because they have been coated rather than filled with polymer.
The polymers in the aqueous (or other) treatment liquid may possess at least a partially hydrophilic polymer component or co-polymer component. Therefore, when the water, i.e., solvent, portion of the coating evaporates, and the polymer, i.e., resin, component has coalesced, dried, polymerized, and/or otherwise fully cured, this partially hydrophilic property of the resin allows water not only to wet the reed""s external surface, but also to penetrate the reed""s internal channels and pores. Remarkably, this aqueous polymer treatment of the natural cane reed has a negligible effect on the mouthfeel and natural water absorbency of the reed, while the durability and the lifetime of the reed are greatly increased. As an additional benefit, the initial break-in period required for new reeds (the time required for a new reed to develop good playing characteristics) is typically shortened by the aqueous (or other) polymer treatment (see below).
In summary, protective coatings formed in reeds according to the present invention, differ from other reed treatments, as the presently described treatment does not block permeation by water, i.e., the reeds are not rendered waterproof.
The term xe2x80x9cwaterproof,xe2x80x9d means that which is xe2x80x9ccovered or treated with a material to prevent permeation by waterxe2x80x9d (Websters Third New International Dictionary, G. and C. Mirriam Company, Springfield, Mass.). While it has been recognized by some inventors that the surface of coated reeds should be wettable by water and saliva, it has not been appreciated that treated reeds should also allow water permeation, i.e., water absorption to occur. In fact, the prior treatments lead away from water-permeability, instead teaching that the reed and its pores should be sealed by any one of several different coating treatments to render the reed waterproof.
In contrast, the present invention suggests that water absorption by the cane reed is an important aspect for preserving the natural vibration and tone properties which characterize the untreated reed. Thus, the present invention involves a process of impregnating the porous cane reed to generate a dried/cured, non-toxic protective polymer coating within and about the water-conductive channels, pores, fibers and woody cells constituting the porous structure of the reed, in which the reed structure remains water-permeable.
On a macroscopic scale, the actual rates of water uptake by untreated, and aqueous polymer-treated reeds were measured gravimetrically by submerging reeds in ambient distilled water for defined periods of time, then removing the reeds and wiping away unabsorbed surface water, and finally measuring the precise weight of the reeds to determine the amounts of water absorbed versus the time submerged (see Examples below).
In one aspect, the present invention features a method for treating the natural cane reed used in woodwind musical instruments. The method includes contacting at least the proximal portion of the reed with a polymer treatment liquid (preferably an aqueous liquid), in which this contacting process delivers at least 1% by weight of polymer into the reed based upon the percentage increase in dry weight of that portion of the reed contacted by the liquid. The reed remains substantially water-permeable, yet is rendered resistant to degradation by saliva.
In a related aspect, preferably following the above polymer liquid contacting, the liquid is removed from the surface of the treated reed, allowing the polymer components within the reed to dry or cure and become water-insoluble. For example, the liquid can be wiped away. The surface can further (or alternatively) be cleaned to remove polymer from the surface with an appropriate solvent.
In preferred embodiments, the polymer treatment liquid is water-based and non-toxic.
In preferred embodiments, the polymer treatment liquid is selected from the group consisting of aqueous polyurethanes, aqueous polyacrylates and combinations thereof.
In yet another preferred embodiment, the polymer treatment liquid contains between 10% and 60% (inclusive) by weight polymer solids. More preferably, the polymer treatment liquid contains between 20% and 50% by weight polymer solids. In particular embodiments, the polymer treatment liquid contains 10 to 40%, 30 to 60%, 20 to 40%, or 30 to 50%.
In another aspect, the present invention features a method for treating the natural cane reed used in woodwind musical instruments. The method includes contacting the reed with a polymer treatment liquid (preferably aqueous). The reed absorbs at least one-third of the amount of polymer absorbed by an equivalent untreated reed contacted with the same liquid for 10 hr at 22xc2x0 C. and 1 atmosphere pressure, where determination of the amount of polymer absorbed is based upon the percentage increase in dry weight of the reed. The reed remains substantially water-permeable, yet is rendered resistant to degradation by saliva. Preferably the reed absorbs at least 40%, 50%, 60%, 70%, 80% 90%, 100% or even more of the amount of polymer absorbed under the above specified conditions.
Preferably following the above liquid contacting, the liquid is removed from the surface of the treated reed, allowing the polymer components within the reed to dry or cure and become water-insoluble. Alternatively, polymer is removed from the surface after at least partially drying or curing, e.g., with an appropriate solvent, or by abrasion or scraping.
In preferred embodiments, the polymer treatment liquid is water-based and non-toxic.
In preferred embodiments, the polymer treatment liquid is selected from the group consisting of aqueous polyurethanes, aqueous polyacrylates and combinations thereof.
In preferred embodiments, the polymer treatment liquid contains between 10% and 60% (inclusive) by weight polymer solids. More preferably, the polymer treatment liquid contains between 20% and 50% by weight polymer solids. In other embodiments, the polymer treatment liquid contains 10 to 40%, 30 to 60%, 20 to 40% or 30 to 50%.
In another aspect, this invention features a method for treating the natural cane reed used in woodwind musical instruments. The method includes the steps of providing a non-toxic (preferably waterborne) polymer treatment liquid, and contacting at least the proximal portion of the reed with the liquid. At least 1% by weight of polymer is delivered into the reed, based upon the percentage increase in dry weight of that portion of the reed contacted by the liquid. Subsequently, contact between the reed and the liquid is ceased, and the liquid is removed from the surface of the reed. Finally, the polymer components within the reed are allowed to dry or cure and become water-insoluble. The reed remains substantially water-permeable, yet is rendered resistant to degradation by saliva.
In another aspect, the present invention provides a natural cane reed for a musical instrument, in which the reed has been impregnated with a polymer treatment liquid (preferably aqueous). At least the proximal portion of the reed has been impregnated by a liquid which contains a non-toxic polymeric material that is water-insoluble upon drying or curing within the reed. The impregnated portion of the reed is at least 25% as permeable to water as an identical portion of an equivalent untreated reed, yet is resistant to degradation by saliva.
In another aspect, a natural cane reed for a musical instrument is provided, in which at least the proximal portion of the reed has been impregnated by a polymer treatment liquid that contains a non-toxic polymeric material that is water-insoluble upon drying or curing within the reed. The impregnated portion of the reed contains at least 1% by weight of the polymer material, based upon the percentage increase in dry weight of the impregnated portion. The impregnated portion of the reed remains substantially water-permeable, yet is resistant to degradation by saliva.
In a preferred embodiment, the non-toxic polymeric material is selected from the group consisting of polyurethanes, polyacrylates and combinations thereof.
In another embodiment, the polymeric material is removed from the surface of the impregnated portion of the reed before the polymeric material has dried or cured, thereby enhancing the water-permeability of the impregnated portion of said reed.
In another preferred embodiment, the reed has been treated with a waterborne polymer treatment liquid selected from the group consisting of aqueous polyurethanes, aqueous polyacrylates and combinations thereof.
In still another preferred embodiment, the reed has been treated with a waterborne polymer treatment liquid comprising between 10% and 60% by weight polymer solids. More preferably, the reed has been treated with a waterborne polymer treatment liquid comprising between 20% and 50% by weight polymer solids.
As used herein, the term xe2x80x9cwoodwind musical instrumentsxe2x80x9d refers to, and includes all musical instruments that utilize a removably attached reed as described herein, including clarinets, oboes, bassoons, and saxophones. xe2x80x9cNatural cane reedsxe2x80x9d used in woodwind musical instruments are widely available from commercial sources, and are described herein in considerable detail.
The reed is tapered in thickness, and its proximal end is thinnest (typically 0.003-0.006 inches thick at the tip), making it especially susceptible to degradation by saliva. The xe2x80x9cproximal portion of the reedxe2x80x9d is that portion which is placed in the mouth and subjected to wear and tear by vibration and contact with saliva. At a minimum, the first one-quarter inch, and preferably the first one-half inch of the proximal end portion (i.e., the portion of the reed""s length measured from the proximal end) should be treated with polymer treatment liquid. For example, at a distance of 0.5 inches from the proximal end of a typical tenor saxophone reed, the reed is still quite thin, ranging from approximately 0.015 to 0.025 inches in thickness, depending upon the distance inward from the side edge of the reed (and varying somewhat among different reed manufacturers). More preferably, at least 0.75, 1.0, and 1.5 inches of the proximal end of the reed are treated with polymer treatment liquid. One inch inward from the proximal end of the tenor reed, the reed""s thickness has approximately doubled (compared to its thickness at the 0.5 inch position). The other end of the reed, i.e., the distal or heel portion, is robust and is removably attached to the instrument (e.g., to the mouthpiece). The heel portion is not significantly contacted or degradated by saliva.
xe2x80x9cPolymer treatment liquidsxe2x80x9d as used herein for impregnating reeds are described above in considerable detail. These liquids may be solvent-borne or water-borne polymer solutions, emulsions and the like. Non-toxic water-based polymer treatment liquids are preferred. For example, polyrethanes, polyacrylates and combinations thereof are available in either solvent or non-toxic waterborne coating systems.
The term xe2x80x9cnon-toxicxe2x80x9d is meant to indicate that the dried coating contains no substantial amount of toxic heavy metals or other toxic materials which could be released into the musician""s mouth while playing the treated reeds.
The term xe2x80x9ccontactingxe2x80x9d refers to physical contact between the cane reed and the polymer treatment liquid, e.g., submersion of the reed in the polymer liquid. One convenient means of submerging a reed in a polymer liquid is to nearly fill a cylindrical vial (e.g., a plastic or glass xe2x80x9cshell vialxe2x80x9d measuring xc2xe-xe2x85x9e inch in diameterxc3x973.5 inches tall) with polymer liquid, then place the reed(s) with their thin edge downward into the liquid, and finally cap the vial. A duration of liquid contact between the reed and the polymer treatment liquid of between two and four hours (by submersion in polymer treatment liquid) is typically sufficient for the desired extent of polymer penetration of the reed. Polymer penetration may or may not reach saturation, i.e., that amount of polymer in the reed at which, little or no additional polymer solids will enter the reed with continued polymer liquid contact. At completion of the polymer contacting treatment of the reed, excess or free polymer liquid is removed from the surface of the treated reed. This xe2x80x9cremovingxe2x80x9d may be accomplished, for example, by wiping the wet reed with an absorbent sheet such as a low lint paper towel. Solvent, e.g., water evaporation allows the polymer components in the liquid within the reed to dry or cure and become water-insoluble. After reeds have been fully immersed in polymer treatment liquid for approximately 10 hours at room temperature (22∞ C.) under ambient conditions (1 atmosphere pressure), little if any additional polymer enters the reeds, i.e., the reed""s xe2x80x9cpolymer saturation levelxe2x80x9d has been reached. After fully drying a polymer-soaked reed, it is typical to measure a 3-4% weight increase in the reed. For the purpose of the present invention, a satisfactory polymer treatment must result in an incorporation of at least 1% by weight of polymer into the cane reed (based upon dry weight of that portion of the reed that has been treated). Preferably, the polymer incorporation is 2% by weight, and more preferably 3% to 4% by weight. Alternatively, at least one-fourth (25%) of the reed""s polymer saturation level must be absorbed by the reed (based upon the reed""s maximum dry weight increase from polymer solids, e.g., measured after approximately 10 hours soaking). Preferably, polymer absorption in the treated reed reaches 50%, 60%, or 70%. Most preferably, polymer absorption reaches 80%, 90% or even 100% of the reed""s polymer absorption capacity at saturation.
The term xe2x80x9csubstantially water-permeablexe2x80x9d when used to describe the treated reeds, means that the treated reeds absorb water at a rate (milligrams of water per minute) that is at least 25% as great as the untreated reeds. Preferably, the water absorption rate is 50% as great, and more preferably 75% or more as great as for an equivalent untreated reed.
The term xe2x80x9cresistant to degradation by salivaxe2x80x9d means that the treated reed resists softening by contact with saliva over a period of days or weeks of playing the instrument using the reed. More specifically, the lifetime of the treated reed is extended at least 100%, i.e., the reed is playable for at least twice as many hours as an equivalent untreated reed. The lifetime of a reed is determined by the number of hours the reed can be played before it reaches the point that a musician finds the reed too soft, unpredictable, unresponsive or lacking in tone response to continue playing. Aqueous polyurethanes, aqueous polyacrylates and combinations thereof (typically constituting the waterborne polymer treatment liquid used to treat reeds herein) are well known in the art, and commercial examples thereof are provided herein. It is preferred that so-called xe2x80x9cinterior finishxe2x80x9d polyurethanes and polyacrylates are used, rather than exterior finishes since the latter typically contain additives including fungicides, mildewcides, UV protectants and other chemicals that are not suitable for contact with the lips and mouth. In fact, the preferred interior finishes contain no persistent additives, i.e., non-volatile additives, that are toxic or that could be irritating or sensitizing to the lips or the mouth. The 10%-60% or 20%-50% or other range of polymer solids in the polymer treatment liquids is chosen so that the polymer liquid will coat rather than fill the channels and pores in the reed, so as to allow entry of water, i.e., capillary flow of water, after the polymer has dried and/or cured in these channels and pores.